This dissertation presents a synchronic and diachronic study of Pingelapese pronouns and auxiliary verbs--"ae", "e", "aen", and "en". Synchronically, Pingelapese employs subject pronominal clitics, not subject agreement markers, unlike Proto-Micronesian and many other contemporary Micronesian languages. Pingelapese also possesses auxiliary verbs that express evidentiality--the speaker's degree of certainty about propositions (ae for low certainty and e for high certainty)--as well as inchoative meaning ("-n"). The combination of evidentiality and inchoative auxiliary verbs yields a realis-irrealis contrast. Comparison with other Micronesian languages reveals that marking evidentiality in this way is unique to Pingelapese. These subject pronouns and auxiliary verbs together compose pronoun-auxiliary complexes. A diachronic study concludes that the root vowel of Proto-Micronesian subject agreement markers was leveled into a uniform vowel ae in Pohnpeic languages. This root vowel ae was innovatively reanalyzed as a low-evidentiality marker, which was accompanied by the development of a high-evidentiality marker e, in the history of Pingelapese. The development of the high-evidentiality marker e from the leveled root vowel ae was achieved through the merger of a following hypothetical high front vowel particle *i (with the high certainty meaning), vowel height assimilation, and final vowel deletion. In contrast, the inchoative morpheme "-n" of "aen" and "en" has a cognate in all Micronesian languages, descending from the Proto-Micronesian "immediateness marker" *nae. Along with the reanalysis of the root vowel of Proto-Micronesian subject agreement markers into evidential markers, the pre-root vowel parts have turned into subject pronominal clitics: "s-" "1dual/pl exclusive", "k-" "2sg", Ø- "3sg", "r-" "3dual/pl". The Pingelapese stand-alone auxiliary verbs developed by extracting "ae", "aen", "e", and "en" from the subject pronoun-auxiliary complexes, leaving the person/number morphemes behind. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]